package com.ruoyi.utils.excel;

import com.alibaba.excel.metadata.Head;
import com.alibaba.excel.metadata.data.WriteCellData;
import com.alibaba.excel.write.handler.CellWriteHandler;
import com.alibaba.excel.write.metadata.holder.WriteSheetHolder;
import com.alibaba.excel.write.metadata.holder.WriteTableHolder;
import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.CellType;
import org.apache.poi.ss.usermodel.Row;
import org.apache.poi.ss.usermodel.Sheet;
import org.apache.poi.ss.util.CellRangeAddress;

import java.util.List;

/**
 * 自定义合并策略
 * @author: Gao Tianle
 * @date: 2023-09-06 17:08
 **/
public class ExcelMergeUtil implements CellWriteHandler {
    private int[] mergeColumnIndex;
    private int mergeRowIndex;

    public ExcelMergeUtil() {
    }

    public ExcelMergeUtil(int mergeRowIndex, int[] mergeColumnIndex) {
        this.mergeRowIndex = mergeRowIndex;
        this.mergeColumnIndex = mergeColumnIndex;
    }

    @Override
    public void beforeCellCreate(WriteSheetHolder writeSheetHolder, WriteTableHolder writeTableHolder, Row row, Head head, Integer columnIndex, Integer relativeRowIndex, Boolean isHead) {

    }

    @Override
    public void afterCellCreate(WriteSheetHolder writeSheetHolder, WriteTableHolder writeTableHolder, Cell cell, Head head, Integer relativeRowIndex, Boolean isHead) {

    }

//    @Override
//    public void afterCellDataConverted(WriteSheetHolder writeSheetHolder, WriteTableHolder writeTableHolder, CellData cellData, Cell cell, Head head, Integer relativeRowIndex, Boolean isHead) {
//
//    }

    @Override
    public void afterCellDispose(WriteSheetHolder writeSheetHolder, WriteTableHolder writeTableHolder, List<WriteCellData<?>> cellDataList, Cell cell, Head head, Integer relativeRowIndex, Boolean isHead) {

        //当前行
        int curRowIndex = cell.getRowIndex();
        //当前列
        int curColIndex = cell.getColumnIndex();

        if (curRowIndex > mergeRowIndex) {
            mergeWithPrevRow(writeSheetHolder, cell, curRowIndex, 0);
//            for (int i = 0; i < mergeColumnIndex.length; i++) {
//                if (curColIndex == mergeColumnIndex[i]) {
//                    mergeWithPrevRow(writeSheetHolder, cell, curRowIndex, curColIndex);
//                    break;
//                }
//            }
        }
    }


    /**
     * 当前单元格向上合并
     *
     * @param writeSheetHolder
     * @param cell             当前单元格
     * @param curRowIndex      当前行
     * @param curColIndex      当前列
     */
    private void mergeWithPrevRow(WriteSheetHolder writeSheetHolder, Cell cell, int curRowIndex, int curColIndex) {
        Object curData = cell.getCellTypeEnum() == CellType.STRING ? cell.getStringCellValue() : cell.getNumericCellValue();
        Cell preCell = cell.getSheet().getRow(curRowIndex - 1).getCell(curColIndex);
        Object preData = preCell.getCellTypeEnum() == CellType.STRING ? preCell.getStringCellValue() : preCell.getNumericCellValue();
        // 将当前单元格数据与上一个单元格数据比较
        Boolean dataBool = preData.equals(curData);
        if (dataBool) {
            Sheet sheet = writeSheetHolder.getSheet();
            //获取所有的合并单元格
            List<CellRangeAddress> mergeRegions = sheet.getMergedRegions();
            boolean isMerged = false;
            for (int i = 0; i < mergeRegions.size() && !isMerged; i++) {
                CellRangeAddress cellRangeAddr = mergeRegions.get(i);
                // 若上一个单元格已经被合并，则先移出原有的合并单元，再重新添加合并单元
                if (cellRangeAddr.isInRange(curRowIndex - 1, curColIndex)) {
                    //按一组移除
                    for (int i1 = 0; i1 < mergeColumnIndex.length; i1++) {
                        cellRangeAddr = mergeRegions.get(i+i1);
                        sheet.removeMergedRegion(i);
                        cellRangeAddr.setLastRow(curRowIndex);
                        sheet.addMergedRegion(cellRangeAddr);
                    }
                    isMerged = true;
                }
            }
            // 若上一个单元格未被合并，则新增合并单元
            if (!isMerged) {
                //按一组合并
                for (int i = 0; i < mergeColumnIndex.length; i++) {
                    CellRangeAddress cellRangeAddress = new CellRangeAddress(curRowIndex - 1, curRowIndex, i, i);
                    sheet.addMergedRegion(cellRangeAddress);
                }
            }
        }
    }

}
